Those
who meditate should remain so alert while meditating that the attention
is kept on the space and not on any movement or vibration, either of
thought or word, idea or imagination

In order to understand this
clearly, notice that when you repeat the mantr or word, your attention
should be on the space between the words spoken or felt inside. No
doubt you will find it hard because of your habit of always paying
attention to some visible or audible form while interacting with the
objects of this world. It is certainly possible that you can develop
the habit by practicing and constantly putting the attention on the
space between any thoughts or words which you repeat, hear, or perceive.

For example, when you are perfectly
still or in kumbhak state on all levels, you can hear the heartbeat
or some pulsation in the space of your physical being. Put the attention
on the space between the two pulsating sounds. If the first beat is one and
the second beat is two, your attention should be in between
the two beats. I assure you that the result will be the expansion of
your consciousness, even to the extent that you will hardly be able
to hear the beat as you did previously. Soon after, you will hear the
pulsation on some deeper or higher level of your finer consciousness.
Now again use the same technique or formula of being constantly aware
and of paying attention to the space between two successive beats.

After hearing or reading this,
stop for a while and close your eyes and perceive that which is going
on within, either in the form of images visualized by the inner eye,
or in the form of any sounds or pulsations. Pay attention between repetitions
of any one form and see the miracle. Your consciousness will be focused
on the formless and the result will be formlessness. So will be the
case when you open your eyes and watch the forms as they appear. You
will develop a habit of paying attention to the space. Your pattern
of mental consciousness will be bodylessness and formlessness. This
will unfold that quality which perceives the highest  the essence
of all the forms, thoughts and images. Soon, after enough practice,
the consciousness will become so pure and formless that it will be
able to grasp the underlying awareness, the essence of the Self, the
God in essence, the ultimate truth from where all the forms of God
incarnate.

This should be treated as a
most fundamental truth  a revealed guidance from the highest
and purest, to be put into practice and used daily. In this way, the
bound consciousness of not only one person but of the whole human race
will be liberated.